1. Field of the Invention
This invention relates to a non-aqueous bleach-containing formulation for washing or cleaning which, besides the bleaching agent, contains nonionic and anionic surfactants and also builders and to a process for the production of this formulation.
2. Statement of Related Art
Water-based washing and cleaning formulations generally contain anionic and nonionic surfactants. However, it has been found to be extremely difficult to incorporate bleaching systems in such formulations. In practice, therefore, bleaching systems are often not used in formulations of the type in question which results in a reduction in their washing performance against bleachable soils. Some liquid detergents available on the market contain very special bleaching systems which, unfortunately, either have very low oxidation potentials or are unstable and decompose even after only brief storage so that there is no improvement in washing activity against bleachable soils.
Various liquid detergent compositions which may contain bleaching agents are described in the literature.
European patent application 30 096, for example, describes non-aqueous liquid detergents of liquid nonionic surfactants which may contain 20 to 70% by weight of builders and 1 to 20% by weight of bleaching agents in suspended form. If desired, these detergents may contain anionic surfactants, such as alkyl benzene sulfonates, olefin sulfonates, alkyl sulfates or soap, optical brighteners, dyes, fragrances or enzymes.
EP-B-0 460 810 describes a non-aqueous liquid dishwashing detergent which contains a non-aqueous organic carrier liquid and at least one component selected from organic cleaning agents, builders, foam inhibitors and mixtures thereof and one component selected from a non-abrasive quantity of 0.5 to 10% of small substantially water-insoluble particles of silicon dioxide, aluminium oxide or titanium oxide or mixtures thereof as anti-film forming agents. The described detergent may also contain 3 to 15% by weight of bleaching agent.
WO 94/01524 describes a substantially non-aqueous liquid detergent which, besides nonionic surfactant, contains up to 60% by weight of builder and between 5 and 35% by weight of bleaching agent. The liquid detergent composition described in this document additionally contains a polymer compound which reduces the viscosity of the dispersion of the solid builders and bleaching agents in the nonionic surfactant in order to obtain a free-flowing and pourable composition.
German patent application 36 26 572 describes a liquid detergent containing a builder, more particularly polyacetal carboxylate, an anti-geling agent and an anti-sedimentation agent dispersed in a liquid nonionic surfactant.
Storable bleach-containing liquid detergents can only be obtained when the bleaching agent is present in the form of a stable dispersion. Commercially available liquid detergents known from the documents cited above have the disadvantage that further auxiliaries are required to obtain a stable dispersion. Since the dispersion present in commercial liquid detergents is limited in its stability, bleaching agents and enzymes cannot be incorporated alongside one another in these products because the enzymes are destroyed by the bleaching agent.
Another problem known from the prior art is that liquid detergents tend to gel, particularly when they are stored at low temperatures or are used at low washing temperatures. The effect of gelation is that the liquid detergents show poor solubility so that, on the one hand, their washing power is affected and, on the other hand, the detergent cannot be completely emptied from the dispensing compartment or a typical dispensing aid while the washing machine is in operation. The gel is very difficult to redisperse in the detergent composition. In addition, gelation leads to a distinct increase in viscosity which in turn affects the dispensing behavior of the liquid detergent. On the other hand, the viscosity of the liquid detergent should not be too low in order to prevent sedimentation of its solid constituents.